JPH107426A - Mold and molding process - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique for precision molding of optical lenses or glass-made optical elements having fine unevenness pattern on their surfaces. SOLUTION: The molds for molding glass 2, 3, 4 into which glass materials 1a-1e are introduced has finely patterned diffraction gratings on their one face, respectively and constituted with sleeve 5 (axis deflection inhibitor). The molds 2, 3, 4 are made of silicon carbide, the optical surface is polished, then coated with a resist for forming fine patterns, transferred by the contact exposure process with a photomask and etched to form a pattern with grooves of 1several μm width and 0.25μm depth. The raw materials to be molded 1a-1e are introduced between the molds 2, 3a-3d, 4. At this time, a positioning tool is used so that each material to be molded may be arranged on the center of the mold. They are set to a molding machine except the sleeve 5, the material is softened with heat and an extruding bar is used to effect press-molding at 640 deg.C under a reduced pressure of 10<-2> torr for 1 minute, and the molded product is taken out of the mold after cooling.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a molding die and a molding method. In particular, the present invention relates to a technique for precisely molding an optical lens or a glass optical element having a fine groove or a concavo-convex pattern on the surface.

[0002]

2. Description of the Related Art In recent years, a method of molding a glass lens with high precision without polishing after pressure molding has been actively practiced. One example of such a method is disclosed in JP-A-52-45.
No. 613 discloses a method. According to this method, first, the temperature of the glass material and the mold are raised to near the softening point of the glass in a non-oxidizing atmosphere. Then, when the temperature of the glass and the mold becomes substantially equal, the glass is pressed by the mold.
Thereafter, the mold temperature is lowered to the glass transition point or lower while maintaining the pressure, and the molded product is taken out by cooling under normal pressure.

There is also known a technique for precisely molding a glass optical element having a fine groove or a concavo-convex pattern on the surface [JP-A-62-203101, JP-A-64-52].
620, JP-A-1-145342, JP-A-2-51434, JP-A-4-175228]. Both methods basically use a mold having a fine pattern on a molding surface and transfer the pattern to glass to precisely mold the glass optical element.

[0004] The above-mentioned precision molding method is excellent in that it is not necessary to perform polishing or surface treatment after removing the molded article, but the cycle time required for molding is long, and practically, the method is more effective. There is a demand to produce more molded articles in a short time. Therefore, a method for efficiently manufacturing many molded articles has been studied, and a new mold has been developed for molding glass lenses. For example, Japanese Patent Application Laid-Open No. 63-64931 discloses a molding die having an upper die, a plurality of intermediate dies, and a lower die arranged in the axial direction of the pressing force in order, and a body die surrounding these. . If a molding material is introduced between the upper mold and the intermediate mold and between the intermediate mold and the lower mold, and then heat-softened and pressure-molded, a large number of molded articles can be manufactured at one time. Also, JP-A-1-176
No. 240 also discloses a mold having an upper mold, an intermediate mold, a lower mold, and a body mold surrounding them.

[0005]

However, these molds have a problem that the heating efficiency is extremely poor because of the body mold surrounding the upper mold, the lower mold and the intermediate mold. That is, in order to heat the upper mold, the lower mold, and the intermediate mold, it is essential to first heat the body mold to a sufficient temperature. Since it is necessary to raise the temperature to soften the molding material, the energy and time required for heating the barrel die are considerably large. In particular, when it is desired to obtain a large number of molded products, disadvantages in terms of cost are inevitable. In addition, a molding die composed of a plurality of dies has a high risk of axial misalignment when a molding material is introduced or when pressure is applied. If an axis shift occurs when the molding material is introduced, a molded product having a desired pattern in a target portion cannot be obtained. Also, if the axis shift occurs during pressurization,
In addition, the wall thickness becomes uneven, and the risk of protrusion or breakage of the molding material increases. For this reason, there is also a problem in molding by removing the body mold from the conventional mold. Furthermore, it has not been known that a glass optical element having a fine concavo-convex pattern or the like is obtained by layering molds to obtain a large number of molded articles at once. When patterns are provided on the upper and lower surfaces, it is necessary to precisely position the mold in order to match the upper and lower patterns, and when the molds are layered, the positioning becomes more and more difficult. Due to such various problems, satisfactory methods cannot be efficiently produced by the conventional method. Also, there is no literature that suggests a solution to such a problem.

Accordingly, the present inventors have addressed the various problems, and have an object to provide a method for efficiently producing a large number of satisfactory molded articles and a molding die capable of implementing the method. The enthusiastic study was carried out. In addition, the present inventors provide a method capable of stably producing a precision molded body having a groove or a concavo-convex pattern while suppressing the time and energy required for molding and a mold capable of performing the method. Also aimed.

[0007] That is, an object of the present invention is to provide a molding die, an auxiliary tool therefor, and a molding method capable of efficiently heating a large number of molding materials when producing a large number of molded products at one time. Further, the present invention provides a molding die and a molding method capable of efficiently heating a large number of molding materials when manufacturing a large number of molded products at one time, and also capable of preventing or positioning the mold from being misaligned. It is in.

[0008]

These objects have been achieved by the present invention described below. The present invention provides an upper mold having a molding surface on a lower surface, a lower mold having a molding surface on an upper surface, one or more intermediate molds having molding surfaces on both upper and lower surfaces, and a molding die having an axis deviation preventing member, The slip prevention member is an upper mold,
The present invention relates to a molding die characterized in that part or all of the side surfaces of an intermediate die and a lower die have an open structure.

The present invention also provides an axis for aligning an upper mold having a molding surface on a lower surface, a lower mold having a molding surface on an upper surface, and a mold having at least one intermediate mold having molding surfaces on both upper and lower surfaces. An alignment jig, wherein the alignment jig comprises at least two members that scissors a mold from the side.

Further, according to the present invention, two adjacent dies, an upper die having a molding surface on a lower surface, a lower die having a molding surface on an upper surface, and a mold having one or more intermediate dies having molding surfaces on both upper and lower surfaces, are opposed to each other. Introducing the molding material between the molding surfaces and aligning the axes of the upper mold, the intermediate mold and the lower mold, and heating the introduced molding material directly from the side surfaces of the upper mold, the lower mold and the intermediate mold to soften the material. A molding method characterized by including a step, a step of applying pressure to the upper mold and / or the lower mold or both of them to press-mold a molding material, and a step of cooling an obtained molded article (first molding method) About.

In addition, the present invention provides two adjacent dies, namely, an upper die having a molding surface on a lower surface, a lower die having a molding surface on an upper surface, and a molding die having one or more intermediate dies having molding surfaces on both upper and lower surfaces. Introducing the molding material between the molding surfaces facing each other and aligning the axes of the upper mold, the intermediate mold and the lower mold, heating the introduced molding material directly from the side surfaces of the upper mold, the lower mold and the intermediate mold. Softening the upper mold, the middle mold and the lower mold while preventing axial misalignment, applying pressure to the upper mold, the lower mold or both, and press-molding the molding material, and including a step of cooling. The present invention relates to a characteristic molding method (second molding method).

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a molding die, a shaft aligning jig and a molding method according to the present invention will be described in detail in order. The molding die of the present invention is characterized in that the axis deviation preventing member has an open structure without covering part or all of the side surfaces of the upper die, the intermediate die and the lower die. The molding die of the present invention includes an upper die, an intermediate die, a lower die, and a shaft deviation preventing member. Molding surfaces are formed on the lower surface of the upper mold, the upper and lower surfaces of the intermediate mold, and the upper surface of the lower mold, and molding is performed between adjacent molds. That is, a molding material is introduced between adjacent dies, softened, and then a plurality of materials are molded at once by pressing the upper die, the lower die, or both. When pressure molding is performed using a molding die having an intermediate mold as described above, the pressing force flows in the lateral direction, and the mold is likely to be misaligned.

The shaft deviation preventing member of the molding die according to the present invention addresses this point. That is, the shaft misalignment preventing member is a member that prevents the upper mold, the middle mold, and the lower mold from sliding in the horizontal direction, and prevents the vertical axis passing through the upper mold, the middle mold, and the lower mold from bending. In a conventional molding die, a body die (sleeve) is used for the purpose of preventing axial misalignment. But,
When such a drum is used, heating of the molding material in the molding die is performed by a heating device outside the drum, so that heating of the molding material is hindered by the drum, and as a result, heating takes a long time. Will be. On the other hand, the shaft deviation preventing member of the present invention has an open structure that does not cover most or all of the side surfaces of the upper mold, the intermediate mold, and the lower mold, so that the molding material in the molding mold can be easily heated. Heating time can be shortened.
In consideration of the heating efficiency, the open portion of the side surface of the molding die of the shaft deviation preventing member is at least 50%, preferably at least 80%, more preferably at least 90% of the side surface of the upper die, the intermediate die and the lower die.

As one embodiment of such an axial deviation preventing member, a frame member and a guide pin which are in contact with the side surfaces of the upper die, the intermediate die and the lower die can be exemplified (FIGS. 4 and 5). These frame members and guide pins are installed with a narrow clearance with the side surfaces of the upper die, the intermediate die, and the lower die. For this reason,
The lower mold and the intermediate mold slide along the frame members and the guide pins when the molding material is introduced and when the molding material is pressed, and are prevented from sliding outside the frame members and the guide pins. It is preferable that the number of pillars and the number of guide pins of the frame member are each three or more. Further, if the inside of the support or the guide pin is processed to have a curvature or an angle corresponding to the side surface of the mold, it is possible to more surely prevent the axial deviation (FIG. 6). With such processing, two columns and guide pins are effective. When a guide pin is used, the guide pin is generally supported by an upper support and a lower support.

As another embodiment of the shaft misalignment preventing member, two or more pins penetrating through the periphery of the mold can be exemplified (FIG. 7). This pin passes through the upper mold, the middle mold and the lower mold. If the size of the hole to be drilled in the mold for passing the pin is set so as to have a narrow clearance with the pin, it is possible to more effectively prevent the axial deviation. The number of holes may be one, but preferably two or more. Pin 2
With more than this number, not only the misalignment but also the rotation of the mold can be prevented. If such pins are used, all side surfaces of the upper mold, the intermediate mold, and the lower mold are exposed, and higher heating efficiency can be obtained.

As still another embodiment of the shaft deviation preventing member,
One can exemplify the molding part of the mold and a pin penetrating the molding material (FIGS. 9 and 10). If the size of the hole to be drilled in the mold for passing the pin is set so as to have a narrow clearance with the pin, it is possible to more effectively prevent the axial deviation. However, it is preferable that the hole of the molding material is larger than the hole formed in the mold. This is to prevent the positioning from becoming uncertain due to the difference in the coefficient of thermal expansion (shrinkage) between the molding material and the mold. The number of pins may be one or more. If the cross section of the pin is polygonal, one pin may be sufficient, but if the cross section is circular, 2
It is preferable to provide more than one. Even when such pins are used, all the side surfaces of the upper mold, the intermediate mold, and the lower mold are exposed, so that the heating efficiency can be sufficiently increased. Note that this embodiment is effective in a case where the obtained molded body can be commercialized by cutting or the like in a subsequent step, thereby removing a portion of a hole formed for passing a pin. That is, 1
This is effective for, for example, a diffraction grating product, which can be obtained by cutting out a plurality of products from a single molded product.

The upper mold, the intermediate mold,
As the lower mold, one having a conventionally used shape and material can be used. For example, JP-A-63-6493
No. 1, JP-A-1-176240, JP-A-62
-203101, JP-A-64-52620, JP-A-1-145342, JP-A-2-514
No. 34, Japanese Unexamined Patent Publication No. 4-175228, the upper mold, the intermediate mold, and the lower mold can be used. It is preferable to make the mold a shape other than a perfect circle, particularly a square shape, because rotation can be easily prevented. The material is selected from those that do not undergo excessive deformation or deterioration due to heating during the molding process. For example, a cemented carbide hardly containing a metal binder can be used.

A molding surface is provided on the lower surface of the upper die, the upper and lower surfaces of the intermediate die, and the upper surface of the lower die. The shape of the molded product is determined by the combination of the lower surface of the upper die and the upper surface of the intermediate die, the lower surface of the intermediate die and the upper surface of the intermediate die adjacent thereto, and the lower surface of the intermediate die and the upper surface of the lower die. Generally, one molding surface is provided on each of the lower surface of the upper die, the upper and lower surfaces of the intermediate die, and the upper surface of the lower die, but a plurality of molding surfaces may be provided.
Further, the intermediate mold having the molding surfaces on both surfaces may be a mold in which two molds each having a molding surface on one surface are bonded together through the back surface. The molding surface is set in consideration of shrinkage of the molding material after heat molding. Further, in the present invention, a fine pattern can be formed on a part or all of the molding surface. The processing of the molding surface can be performed using a technique well known in the field of the present invention, and examples thereof are given in Examples described later.

The number of intermediate molds constituting the mold of the present invention is one.
Above. If the number of intermediate molds is m and the number of molding surfaces provided on one surface of the mold is n, (m +
1) xn molded articles can be manufactured. However,
If the number of m of the intermediate mold is increased too much, care must be taken because unevenness in pressure propagation during pressure molding may make it difficult to produce a uniform molded product.

The mold of the present invention can be provided with a mold spacing member as desired. However, it is preferable from the viewpoint of efficient heating that the mold interval determining member has a shape and structure that can maintain the open state of the side surface of the molded product between the molds. The mold interval determining member is means for determining the interval between the upper mold and the intermediate mold, the interval between the intermediate mold and the adjacent intermediate mold when there are a plurality of intermediate molds, and the interval between the intermediate mold and the lower mold. When molding using the mold of the present invention, a molding material is first introduced between the molds. At this time, the space between the molds is normally opened by the thickness of the introduced molding material.
Thereafter, when pressure is applied, the distance between the dies is reduced, and the dies and the die distance determining member come into contact with each other and are maintained at a constant distance between the dies. At this time, the mold interval determining member determines the thickness of the molded product and plays a role in preventing the molding material from protruding during the pressure molding. The mold interval determining member also plays a role of assisting in preventing the upper and lower molding surfaces from being displaced due to the inclination of the intermediate mold during the pressure molding.

As shown in FIG. 8, for example, the mold spacing determining member may be a ring-shaped member 16 in which a pin 18 as an axial deviation preventing member penetrates the center thereof.
In addition, the mold interval determining member may be fixed in advance to either the upper mold or the lower mold. In addition, the mold interval determining member may be provided as an independent member for each mold, or one member may determine between a plurality of molds. As an example of the latter, for example, a single member fixed to both the upper and lower surfaces of the intermediate mold, whereby the distance between the intermediate mold and the mold above it, and the distance between the intermediate mold and the mold below it Can be determined. Further, by appropriately replacing the mold spacing determining member with a desired shape, molded articles having different thicknesses can be simultaneously prepared using the same mold.

The material of the mold interval determining member is selected from those which can withstand heating during the molding process. In particular, it is preferable to use a material having a higher coefficient of thermal expansion than the molding material used. By providing a mold spacing member made of such a material, it is possible to cool under pressure while keeping the upper and lower surfaces of the molded body in contact with the mold after pressure molding. That is, since the thickness shrinkage of the mold interval determining member is larger than that of the molded body, the pressing of the molded body from the upper and lower molds is maintained even in the cooling step. Thereby, the upper and lower sides of the molded body can be brought into contact with the mold and cooled through the transition point in a pressurized state, and the surface accuracy can be improved.

In the first molding method of the present invention, when the molding material is introduced into the molding die, the axes of the upper mold, the intermediate mold and the lower mold are aligned, and the introduced molding material is moved upward. It is characterized by direct heating and softening from the side of the mold, lower mold and intermediate mold. In order to achieve both alignment of the mold and direct heating, a jig for aligning the mold is removed from the side of the mold after the alignment and before heating. More specifically, a conventionally known body mold (sleeve) can be used as a jig for axis alignment, and the body mold can be removed after axis alignment. This method
This is shown in FIG. In (a), after the alignment of the mold is performed using the sleeve 5, the sleeve 5 is removed from the side surface of the mold, and heated and pressed.

The alignment of the molding die may be performed by aligning an upper die having a molding surface on a lower surface, a lower die having a molding surface on an upper surface, and one or more intermediate dies having molding surfaces on both upper and lower surfaces. The jig may be formed by at least two members for inserting a mold into the mold from the side. FIG. 3 shows an example of such a shaft alignment jig. The axis aligning jig shown in FIG. 3 includes two members 11 for scissoring the mold from the side, and after the axis alignment, the two members move to a position away from the mold before heating. Can be directly heated.

Further, the positioning of the molding material can be performed together with the alignment of the molding die. For example, for aligning jigs, an upper die having a molding surface on a lower surface, a lower die having a molding surface on an upper surface, and a molding die having one or more intermediate dies having molding surfaces on both upper and lower surfaces are provided. Wherein the alignment jig comprises at least two scissor members for scissoring the mold from the side, and the scissor member positions the molding material introduced into the mold. Has a molding material pressing part that can be inserted between the molds,
In addition, a shaft alignment jig in which the number of the molding material pressing portions is at least three in the entire shaft alignment jig can be given.
FIG. 2 shows an example of such a shaft alignment jig. The axis aligning jig shown in FIG. 2 includes two scissoring members 9 for scissoring the mold from the side, and each scissoring member has two molding material pressing portions 10. This axis alignment jig can directly heat the molding material in the mold by moving the two members away from the mold after the axis alignment and before heating.

Since the type of molding material to be used is not particularly limited, glass materials and the like can be widely used.
It is typical to use one type of molding material for one molding die, but in some cases, two or more types of molding materials may be properly used according to the molding surface. When a mold having a square mold is used, it is preferable that the molding material is also square. This is because rotation can be more easily prevented, and the efficiency of cutting in the subsequent process is high.

According to a second molding method of the present invention, when introducing a molding material into a molding die, the axes of an upper mold, an intermediate mold and a lower mold are aligned, and the introduced molding material is subjected to an upper mold and a lower mold. It is characterized in that it is heated directly from the side of the intermediate mold to soften it, and that the pressure molding of the molding material is carried out while preventing axial misalignment. It is preferable that the second molding method is performed using the molding die of the present invention having the above-described axis deviation preventing member. Also in the second molding method of the present invention, the type of molding material to be used is not particularly limited, and similarly to the first method, various materials and glass materials having various shapes can be used.

The molding material is introduced between the opposing molding surfaces of two adjacent molds of the mold. When introducing such a molding material, the axes of the upper mold, the intermediate mold, and the lower mold must be aligned. The introduction of the molding material may be appropriately performed while assembling the molding die in consideration of the type of the axis deviation preventing member to be used or the like, or may be introduced into a previously assembled molding die. When obtaining a molded body having a fine pattern on the upper and lower surfaces, it is important to align the fine pattern on the upper and lower surfaces. In this case, not only the alignment but also the positioning of the fine pattern on the upper and lower molding surfaces is performed. Is appropriate. Further, when the pin shown in FIGS. 9 and 10 is used as an axis deviation preventing member, the positioning of the fine pattern and the positioning of the molding material can be performed simultaneously.

After the molding material is introduced, heating is performed. FIG.
Axis-preventing members having guide pins shown in FIGS.
The use of the molding die of the present invention having the axis deviation preventing members consisting of the pins 9 and 10 makes it possible to heat-soften the molding material with high heating efficiency without removing these axis deviation preventing members before heating. it can. After the molding material is softened, pressure is applied to the upper mold, the lower mold or both by applying pressure.
At this time, the pressure may be applied by pressing the center of the upper mold with a rod-shaped body or by applying pressure to the entire surface of the upper mold. In addition, you may pressurize while heating. In addition, in the second molding method of the present invention, since the pressing is performed while the axis deviation preventing member is set, the axis deviation occurs at the time of pressing, the wall thickness becomes uneven, and the molding material is reduced. It has the advantage of not protruding or being damaged.

In both the first molding method and the second molding method of the present invention, known methods can be directly applied to the heating softening condition, the pressing condition and the cooling condition depending on the physical properties of the molding material. A molded product is obtained by cooling after pressure molding. After cooling, the molded product may be cut to a desired size, if necessary, to obtain a desired product.

However, if the molding material is heated in a nitrogen atmosphere, there is an advantage that the burning property is improved. However, when the depth of the groove of the fine pattern on the molding surface is 0.1 μm or more, a gas trap may be generated in which gas is trapped in the groove during molding. For this reason, it is preferable that the temperature is raised in a nitrogen atmosphere, a vacuum state of 10 ⁻¹ torr or less is maintained until the molding material starts to soften and heat molding is started, and the nitrogen atmosphere is returned again during cooling. The reason why the vacuum is not applied at the time of raising and lowering the temperature and the nitrogen atmosphere is used is to improve the temperature distribution by the convection of the nitrogen gas. When heating is performed under reduced pressure, discharge occurs if high-frequency heating is performed. For this reason, it is preferable to heat using an infrared lamp heater under reduced pressure.

In the method of transferring a fine pattern to a molded product, the thickness change of the softened molding material due to pressure is preferably less than 200 μm. More preferably, it is less than 100 μm. If the thickness change is 200 μm or more, the thickness variation may increase when five or more molding materials are molded at one time. In such a case, it is preferable to prevent the inclination of the intermediate mold by using the above-mentioned mold interval determining member, and to surely suppress the variation in the thickness within the allowable tolerance (16a to 16e in FIG. 7). . In addition,
Pressing a molding material heated to a viscosity of 10 ^8.5 to 10 ¹⁰ poise is preferable because the thickness change of the molding material becomes 200 μm or less.

[0033]

The present invention will be further described with reference to the following examples. Example 1 FIG. 1A is a cross-sectional view of a molding die of the present invention into which glass materials 1a to 1e have been introduced. This mold is a mold for manufacturing a flat product having a diffraction grating having a fine pattern on one surface. This mold includes an upper mold 2 having a molding surface on a lower surface, intermediate dies 3a to 3d having molding surfaces on both upper and lower surfaces, a lower mold 4 having a molding surface on an upper surface, and a sleeve (axis deviation preventing member) 5. You. Fine pattern is glass material 1
It is formed only on the upper molding surface as viewed from a to 1e.

The molds 2, 3a to 3d, 4 were prepared by the following method. First, six flat plates each having a diameter of 75 mm made of silicon carbide prepared by a CVD method were prepared, and a surface corresponding to a molding surface was polished to an optical surface. A resist is applied to 5 out of 6 sheets, a fine pattern is transferred to the resist by a contact exposure method using a photomask, and then etched by a reactive ion etching method to obtain a groove width of 1 to several μm.
m, a pattern having a groove depth of 0.25 μm was formed. On each molding surface, a hard carbon thin film was formed as a surface layer, and each molding die was completed.

Using this mold, a flat product having a diffraction grating was formed by the following method. As a molding material, a soda lime glass having a flat surface polished to an outer diameter of 62.5 mm and a thickness of 1.05 mm was used. This glass material 1a ~ 1e,
As shown in FIG. 1A, the molds were sequentially introduced between the molds 23a to 3d and 4. At this time, it set using the positioning tool so that each glass material might be installed in the center part of a type | mold. next,
The glass material is softened by removing the sleeve 5 and setting it in a molding machine, and then heating it.
Pressure molding was performed at 640 ° C. for 1 minute under a reduced pressure of 0 ⁻² torr. This is shown in FIG. Thereafter, the molded product was taken out by cooling. Since the outer diameter of the obtained molded product was 64 mm, which was smaller than the outer diameter of the molding die of 75 mm, there was no problem such as protrusion to the end of the molding die. The thickness of the molded product was 1.00 ± 0.01 mm, and the elongation relative to the thickness of the introduced glass material was 0.05 ± 0.01 mm. The thickness variation was sufficiently within the allowable tolerance, there was no gas trap, and the transferability of the fine pattern was extremely good. The obtained molded product is cut into a lattice shape by a dicing saw in accordance with the alignment mark, and is vertically 2.5 m long.
m, a flat diffraction grating product having a width of 3.5 mm was obtained.

Embodiment 2 In this embodiment, a glass material is positioned using a stepped jig 9 which is a shaft alignment jig having a molding material pressing portion shown in FIG. 2 instead of the sleeve 5 of the first embodiment. Was done. FIG.
(A) is an AA partial cross-sectional view of FIG. 2 (b). The stepped jigs 9 are designed to be paired so as to sandwich the mold from the left and right (see FIG. 2B). One handle 9 is provided with two steps, and each step constitutes a molding material pressing section 10, and this section hits the molding material and is extruded to set the molding material at a predetermined position. And
Alignment of the mold can also be performed. After positioning the molding material at a predetermined position in this way and aligning the axes of the molding dies, the stepped jig was removed, and heating, pressure molding, and cooling were performed as in Example 1. Further, instead of the stepped jig 9, the alignment of the mold can be performed by using a jig 11 having no step shown in FIG. 3. In this case, after heating, the jig 11 having no step can be sandwiched from the left and right again to perform pressure molding. FIG. 3A is a partial sectional view taken along line BB of FIG. 3B. As a result of this example,
In addition to the features of the product obtained in Example 1, a flat product having a diffraction grating at a desired position was obtained.

Example 3 In this example, the molding was performed using a molding die in which the frame member shown in FIG. The frame member 12 shown in FIG. 4 is provided with a narrow clearance from the outer periphery of the mold. When introducing the glass material between the molds, the frame member can be assembled in advance, and the glass material can be introduced while sequentially assembling the molds. Further, the glass material may be introduced while assembling the frame member and the mold in parallel. Furthermore, after assembling the mold into which the glass material is introduced, the assembled mold may be put in the frame. The mold thus assembled was heated, pressed, and cooled in the same manner as in Example 1. Unlike the case of heating by surrounding with a sleeve, in the present embodiment using the frame member, most of the side surfaces of the mold are released, so that the heating efficiency is good. In addition, the glass material could be positioned using a jig as needed.

Embodiment 4 In this embodiment, the member having the guide pin shown in FIG. The guide pin 13 in FIG. 5 is provided with a narrow clearance from the outer periphery of the mold. The guide pin 13 includes an upper support 14 and a lower support 1.
5 is held. The member having the guide pin can be assembled in the same manner as in the third embodiment, and has the advantages that the heating efficiency is good and the glass material can be positioned as required.

Example 5 In this example, a molded article having fine patterns on both upper and lower surfaces was prepared using a molding die having an axis deviation preventing member having a mold rotation preventing function. The basic structure of the molding die used in the present embodiment is the same as the molding die used in the embodiment 4 shown in FIG. That is, the guide pins 13 are connected to the upper support 14 and the lower support 1.
5 is held. However, as shown in FIG. 6, four peripheral portions of each of the upper mold 2, the intermediate mold 3, and the lower mold 4 are cut out, and rotation is prevented by the guide pins 13 made of cemented carbide. The guide pins 13 are held by an upper support 14 (not shown in FIG. 6) and a lower support 15. Regarding the member having this guide pin,
It can be assembled in the same manner as in Example 3, has the advantage of good heating efficiency and positioning of the glass material as required.

Example 6 In this example, a molded product having fine patterns on both upper and lower surfaces was prepared using a molding die having another axis deviation preventing member having a mold rotation preventing function. The basic structure of the molding die used in the present embodiment is the same as the molding die used in the fifth embodiment. However, as shown in FIG. 7 and FIG.
3d, four holes 17 are formed in the periphery of each of the lower molds 4, and a pin 18 penetrates therethrough.
8 is a ring-shaped member 16a to 16 which is a mold spacing determining member.
e also penetrates. The pins 18 are held by the upper support 14 and the lower support 15. The member having the pin can be assembled in the same manner as in the third embodiment, and has the advantages that the heating efficiency is good and the glass material can be positioned as required. In addition, uniform pressurization could be performed because the ring-shaped member was present to play a role in determining the mold interval. For this reason, the dispersion of the obtained molded articles was small, and stable production could be performed.

Example 7 In this example, a molded article having fine patterns on both upper and lower surfaces was prepared using a molding die having an axis deviation preventing member having a function of preventing molding material rotation. The mold used in this example is as shown in FIG. Glass material 1 (Fig. 9 (a)
1a), upper mold 2 (not shown in FIG. 9 (a)), intermediate mold 3 (3a in FIG. 9 (a)), lower mold 4
(Not shown in FIG. 9 (a)), four holes 17 are formed at predetermined positions near the center, and pins 18 penetrate. The size of the hole is larger in the glass material than in the mold. The pin 18 is held by an upper support and a lower support. FIG. 9B is a partial cross-sectional view taken along the line CC of FIG. 9A. The member having the pin can be assembled in the same manner as in the third embodiment, and has the advantages that the heating efficiency is good and the glass material can be positioned as required. The elongation by molding was only about 50 μm. Further, since the hole of the glass material was relatively large near the center, there was no adverse effect due to the difference in the coefficient of thermal expansion between the glass and the mold. The obtained molded product was cut into a lattice shape using a dicing saw in accordance with the alignment mark, and a flat diffraction grating product having a length of 2.5 mm and a width of 3.5 mm was removed except for a portion having holes.

Example 8 In this example, a molded article having a fine pattern on both upper and lower surfaces was prepared using a molding die having another axis deviation preventing member having a molding material rotation preventing function. The mold used in this example is as shown in FIG. Instead of the four holes of the seventh embodiment, an elongated hole 17 is provided near the center, and a stainless steel pin 18 having a larger coefficient of thermal expansion than the mold or the glass material penetrates the hole. Since the size of the pin was slightly smaller than the hole, the glass was not adversely affected during molding. Also, there was no problem during cooling because the pins shrink more.

[0043]

According to the molding die and the molding method of the present invention, it is possible to carry out the heat molding efficiently while preventing the axial deviation of the upper die, the intermediate die and the lower die. For this reason, even if it has a fine pattern, a large number of fixed precision molded products can be molded at once. In particular, in the embodiments shown in Examples 6 to 8, it is possible not only to perform efficient heat molding while preventing axial displacement of the upper mold, the intermediate mold, and the lower mold, but also to match the fine patterns of the upper and lower molding surfaces. This is particularly advantageous for manufacturing products having a diffraction grating.

[Brief description of the drawings]

FIG. 1 is a sectional view of a mold according to the present invention described in Example 1.

FIG. 2 is a sectional view of a stepped jig described in a second embodiment.

FIG. 3 is a sectional view of a stepless jig described in a second embodiment.

FIG. 4 is a perspective view of a molding die of the present invention described in Example 3.

FIG. 5 is a perspective view of a mold of the present invention described in Example 4.

FIG. 6 is a cross-sectional view of the mold of the present invention described in Example 5.

FIG. 7 is a cross-sectional view of the mold of the present invention described in Example 6.

FIG. 8 is a cross-sectional view of the molding die of the present invention described in Example 6.

FIG. 9 is a cross-sectional view of the molding die of the present invention described in Example 7.

FIG. 10 is a cross-sectional view of a molding die of the present invention described in Example 8.

FIG. 11 is a partial cross-sectional view of a mold of the present invention having a fine pattern on both upper and lower surfaces described in Example 5.

[Explanation of symbols]

1: molding material 2: upper mold 3: intermediate mold 4: lower mold 5:
Sleeve 6: Push rod 7: End of push rod 8: Upper surface of sleeve 9: Stepping jig 10: Molding material extruding section 11: Stepless jig 12: Frame member 13: Guide pin 14: Upper support 1
5: Lower support 16: Ring member 17: Hole 18: Pin

Claims (24)

[Claims] An upper mold having a molding surface on a lower surface, a lower mold having a molding surface on an upper surface, at least one intermediate mold having molding surfaces on both upper and lower surfaces, and a molding die having an axis deviation preventing member,
The molding die, wherein the shaft deviation preventing member has a structure in which part or all of side surfaces of an upper die, an intermediate die and a lower die are opened. 2. The molding die according to claim 1, wherein the shaft deviation preventing member has a mold rotation preventing function. 3. The molding die according to claim 2, wherein the axis deviation preventing member has a function of preventing molding material rotation. 4. The molding die according to claim 1, wherein the shaft deviation preventing member is a frame member or a guide pin provided with a narrow clearance with the side surfaces of the upper die, the lower die, and the intermediate die. 5. The molding die according to claim 1, wherein the shaft deviation preventing member is a pin penetrating a peripheral portion of the die. 6. The molding die according to claim 1, wherein the axis deviation preventing member is a pin penetrating the molding part of the die and the molding material. 7. The molding die according to claim 6, wherein the cross section of the pin is a circle, and the number of pins is two or more. 8. The mold according to claim 6, wherein the cross section of the pin is rectangular. 9. The method according to claim 1, wherein the molding surface has a fine pattern.
The molding die according to any one of claims 1 to 8. 10. A shaft aligning jig for aligning a mold having an upper mold having a molding surface on a lower surface, a lower mold having a molding surface on an upper surface, and at least one intermediate mold having molding surfaces on both upper and lower surfaces. Wherein the alignment jig comprises at least two members for scissors the mold from the side. 11. A member for scissoring a molding die from a side surface has a molding material pressing portion that can be inserted between the dies in order to position the molding material introduced into the molding die, and the molding material pressing portion. The axis alignment jig according to claim 10, wherein the number of parts is at least three in the entire axis alignment jig. 12. Opposing molding of two adjacent dies, an upper die having a molding surface on a lower surface, a lower die having a molding surface on an upper surface, and a molding die having one or more intermediate dies having molding surfaces on both upper and lower surfaces. A step of introducing a molding material between the surfaces and aligning the axes of the upper mold, the intermediate mold and the lower mold, a step of heating and softening the introduced molding material directly from the side surfaces of the upper mold, the lower mold and the intermediate mold, A molding method, comprising: a step of applying pressure to an upper mold, a lower mold, or both to form a molding material under pressure, and a step of cooling an obtained molded product. 13. The axial alignment of the molding die in the molding material introduction step by the axial alignment jig according to claim 10, wherein the axial alignment jig is removed from a side surface of the molding die before the heating softening step. Item 13. The molding method according to Item 12. 14. In the molding material introduction step, positioning of the molding material is also performed, and the axis alignment of the molding die and the positioning of the molding material are performed by the axis alignment jig according to claim 11, and before the heating softening step. The molding method according to claim 12, wherein the axis alignment jig is removed from a side surface of the mold. 15. Opposed molding of two adjacent dies, an upper die having a molding surface on a lower surface, a lower die having a molding surface on an upper surface, and a molding die having one or more intermediate dies having molding surfaces on both upper and lower surfaces. A step of introducing a molding material between the surfaces and aligning the axes of the upper mold, the intermediate mold and the lower mold, a step of heating and softening the introduced molding material directly from the side surfaces of the upper mold, the lower mold and the intermediate mold, While preventing the upper, middle and lower molds from misaligning,
A molding method comprising: a step of applying pressure to a lower mold or both of them to press-mold a molding material; and a step of cooling an obtained molded article. 16. The molding method according to claim 15, wherein in the molding material introducing step, a frame member or a guide pin provided with a narrow clearance with the side surfaces of the upper mold, the lower mold and the intermediate mold is installed. 17. The molding method according to claim 15, wherein in the molding material introducing step, a pin penetrating a peripheral portion of at least one die selected from an upper die, a lower die and an intermediate die is provided. 18. The molding method according to claim 15, wherein in the molding material introducing step, a molding part of at least one mold selected from an upper mold, a lower mold and an intermediate mold and a pin penetrating the molding material are provided. 19. The molding method according to claim 12, wherein the molding surface has a fine pattern. 20. The method according to claim 1, wherein the molding material is a glass material.
20. The molding method according to any one of 2 to 19. 21. The softening viscosity of the glass material is 10 ^8.5
The molding method according to claim 20, wherein the pressure is from ^{10 to} 1010 poise. 22. The molding method according to claim 12, wherein the pressure is reduced to 10 ^-1 torr or less from the time when the molding material starts to soften until the time when the pressure molding is started. 23. The molding method according to claim 22, wherein the heating is performed by an infrared lamp heater. 24. The thickness variation by pressure molding is 200 μm.
The molding method according to claim 19, which is less than m.